drivers/pci/hotplug/s390_pci_hpc.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * PCI Hot Plug Controller Driver for System z
   4  *
   5  * Copyright 2012 IBM Corp.
   6  *
   7  * Author(s):
   8  *   Jan Glauber <jang@linux.vnet.ibm.com>
   9  */
  10
  11 #define KMSG_COMPONENT "zpci"
  12 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
  13
  14 #include <linux/kernel.h>
  15 #include <linux/slab.h>
  16 #include <linux/pci.h>
  17 #include <linux/pci_hotplug.h>
  18 #include <asm/pci_debug.h>
  19 #include <asm/sclp.h>
  20
  21 #define SLOT_NAME_SIZE  10
  22
  23 static int zpci_fn_configured(enum zpci_state state)
  24 {
  25         return state == ZPCI_FN_STATE_CONFIGURED ||
  26                state == ZPCI_FN_STATE_ONLINE;
  27 }
  28
  29 static inline int zdev_configure(struct zpci_dev *zdev)
  30 {
  31         int ret = sclp_pci_configure(zdev->fid);
  32
  33         zpci_dbg(3, "conf fid:%x, rc:%d\n", zdev->fid, ret);
  34         if (!ret)
  35                 zdev->state = ZPCI_FN_STATE_CONFIGURED;
  36
  37         return ret;
  38 }
  39
  40 static inline int zdev_deconfigure(struct zpci_dev *zdev)
  41 {
  42         int ret = sclp_pci_deconfigure(zdev->fid);
  43
  44         zpci_dbg(3, "deconf fid:%x, rc:%d\n", zdev->fid, ret);
  45         if (!ret)
  46                 zdev->state = ZPCI_FN_STATE_STANDBY;
  47
  48         return ret;
  49 }
  50
  51 static int enable_slot(struct hotplug_slot *hotplug_slot)
  52 {
  53         struct zpci_dev *zdev = container_of(hotplug_slot, struct zpci_dev,
  54                                              hotplug_slot);
  55         struct zpci_bus *zbus = zdev->zbus;
  56         int rc;
  57
  58         if (zdev->state != ZPCI_FN_STATE_STANDBY)
  59                 return -EIO;
  60
  61         rc = zdev_configure(zdev);
  62         if (rc)
  63                 return rc;
  64
  65         rc = zpci_enable_device(zdev);
  66         if (rc)
  67                 goto out_deconfigure;
  68
  69         pci_scan_slot(zbus->bus, zdev->devfn);
  70         pci_lock_rescan_remove();
  71         pci_bus_add_devices(zbus->bus);
  72         pci_unlock_rescan_remove();
  73
  74         return rc;
  75
  76 out_deconfigure:
  77         zdev_deconfigure(zdev);
  78         return rc;
  79 }
  80
  81 static int disable_slot(struct hotplug_slot *hotplug_slot)
  82 {
  83         struct zpci_dev *zdev = container_of(hotplug_slot, struct zpci_dev,
  84                                              hotplug_slot);
  85         struct pci_dev *pdev;
  86         int rc;
  87
  88         if (!zpci_fn_configured(zdev->state))
  89                 return -EIO;
  90
  91         pdev = pci_get_slot(zdev->zbus->bus, zdev->devfn);
  92         if (pdev && pci_num_vf(pdev)) {
  93                 pci_dev_put(pdev);
  94                 return -EBUSY;
  95         }
  96
  97         zpci_remove_device(zdev);
  98
  99         rc = zpci_disable_device(zdev);
 100         if (rc)
 101                 return rc;
 102
 103         return zdev_deconfigure(zdev);
 104 }
 105
 106 static int get_power_status(struct hotplug_slot *hotplug_slot, u8 *value)
 107 {
 108         struct zpci_dev *zdev = container_of(hotplug_slot, struct zpci_dev,
 109                                              hotplug_slot);
 110
 111         switch (zdev->state) {
 112         case ZPCI_FN_STATE_STANDBY:
 113                 *value = 0;
 114                 break;
 115         default:
 116                 *value = 1;
 117                 break;
 118         }
 119         return 0;
 120 }
 121
 122 static int get_adapter_status(struct hotplug_slot *hotplug_slot, u8 *value)
 123 {
 124         /* if the slot exits it always contains a function */
 125         *value = 1;
 126         return 0;
 127 }
 128
 129 static const struct hotplug_slot_ops s390_hotplug_slot_ops = {
 130         .enable_slot =          enable_slot,
 131         .disable_slot =         disable_slot,
 132         .get_power_status =     get_power_status,
 133         .get_adapter_status =   get_adapter_status,
 134 };
 135
 136 int zpci_init_slot(struct zpci_dev *zdev)
 137 {
 138         char name[SLOT_NAME_SIZE];
 139         struct zpci_bus *zbus = zdev->zbus;
 140
 141         zdev->hotplug_slot.ops = &s390_hotplug_slot_ops;
 142
 143         snprintf(name, SLOT_NAME_SIZE, "%08x", zdev->fid);
 144         return pci_hp_register(&zdev->hotplug_slot, zbus->bus,
 145                                zdev->devfn, name);
 146 }
 147
 148 void zpci_exit_slot(struct zpci_dev *zdev)
 149 {
 150         pci_hp_deregister(&zdev->hotplug_slot);
 151 }